Electric vacuum cleaner

ABSTRACT

The electric vacuum cleaner is disclosed which includes a main body within which an electric blower and cyclonic separation cylinder are provided. A dust collecting case is provided in communication with the cyclonic separation cylinder to receive dust that has been separated from the inlet tube. The dust collecting case also includes a filter arranged therein. Air received from the inlet tube is separated such that a portion is passed through the dust collecting case and a communicating passage. The air is subsequently merged and discharge through the electric blower.

This application is a Divisional application of application Ser. No.10/372,087, filed Feb. 25, 2003, which claims priority from Japanesepatent applications JP 2002-169405, filed on Jun. 11, 2002, and JP2002-305265 filed on Oct. 21, 2002, the contents of which areincorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention is related to an electric vacuum cleaner.

A general electric vacuum cleaner is so constructed to take in dirty airthrough a floor nozzle, introduce it into the body of the vacuumcleaner, clean the air through a dust collector in the vacuum cleaner,and exhaust the cleaned air to the outside of vacuum cleaner. The dustcollector captures dust by filtration using a paper filter or bycentrifugal separation using a cylindrical separation cyclone to cleanthe air.

Japanese Application Patent Laid-Open Publication 2001-29288 disclosesan electric vacuum cleaner with a cyclonic separation type dustcollector. The dust collector in the electric vacuum cleaner is soconstructed that one cyclonic separation cylinder may capture dust indirty air by centrifugal separation.

Published Japanese translations of PCT international publication forpatent applications 1880 discloses, as a cyclonic separation dustcollector in an electric vacuum cleaner, a dust separator having acyclonic separation type dust collector comprising outer and innerseparation cylinders in which the outer separation cylindercentrifugally removes relatively large particles and the innerseparation cylinder centrifugally removes fine particles.

For general home electric vacuum cleaners, it is most important thatthey are compact and convenient in handling. Further, their dustcollector must be smaller and the collected dust must be disposed ofeasily.

The dust collector having a single cyclonic separation cylinder catchesboth large and fine dust particles together. This cannot prevent finedust from being easily raised up when it is taken out from the vacuumcleaner for disposal. Further, the cyclonic separation cylinder must belonger and greater to increase the dust catching ability (or collectingand cleaning ability).

A dual-cylinder type cyclonic dust separator (dust collector) has acombination of inner and outer separation cylinders, but it is verydifficult to make it compact and convenient in handling. For generalhome use, lots of large dust particles are captured and must befrequently taken out from the vacuum cleaner. In this dust separatorconfiguration, it is impossible to take out only the outer cylinder thatcaptured large dust particles for disposal.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anelectric vacuum cleaner with a compact and easy-to-handle cyclonicseparation type dust collector.

It is yet a further object of the present invention to provide anelectric vacuum cleaner with a compact cyclonic separation type dustcollector that has a high dust collecting performance.

It is a still further object of the invention to provide an electricvacuum cleaner having a cyclonic separation type dust collector that canfirmly hold the collected fine particles.

The above described objects can be attained by an electric vacuumcleaner equipped with a cyclonic separation cylinder that centrifugallycleans dirty air, wherein the central axis of the cyclonic separationcylinder is made vertical to the floor when the vacuum cleaner cleansthe floor and that the cylinder has an inlet to take in dirty air on thebottom of the cylinder, an outlet to exhaust clean air on the bottom ofthe cylinder, and a communicating port with a dust collecting case onthe side of the cylinder.

This invention is characterized in that the electric vacuum cleaner isequipped with a cyclonic separation cylinder including an internalcylinder having an air outlet, a dust collecting case communicating withthe cyclonic separation cylinder through an communicating port formed onthe cyclonic separation cylinder, a filter in the dust collecting case,and a fluid passage in which the clean air passing through the filtermerges with the air discharged from the air outlet.

This invention is further characterized in that dust captured in thedust collecting case is taken out from the electric vacuum cleaner byopening and closing the filter.

This invention is furthermore characterized in that the cyclonicseparation cylinder and the dust collecting case are detachable.

This invention is further characterized in that the electric vacuumcleaner is equipped with a cyclonic separation cylinder which takes indirty air through the bottom of the cylinder from a floor nozzle duringvacuum-cleaning, centrifugally de-dusts, then discharges the clean airto the outside of the cylinder though the bottom of the cylinder, andthat the axis of the cyclonic separation cylinder is approximatelyvertical to the floor and the rotating shaft of the motor-driven blowerwhich is an air driving source is horizontal.

This invention is further characterized by an electric vacuum cleanercomprising a motor-driven blower that is an air driving source and acyclonic separation cylinder that centrifugally removes dust from dirtyair taken in from the floor nozzle during vacuum-cleaning and dischargesthe clean air to the outside of the cylinder and has its axisapproximately vertical to the floor, wherein the air inlet port is inthe center (when viewed from the top), the cyclonic cleaning means ismoved a little to the left or right from the center, and themotor-driven blower is positioned opposite to the cyclonic separationcylinder relative to the center.

This invention is further characterized in that the electric vacuumcleaner is equipped with a dust collecting case which communicates withthe cyclonic separation cylinder through an opening formed on thecylinder, that the dust collecting case includes an air filter, and thata fluid passage is formed under the outlet of the cyclone to merge theclean air passing through the filter with the air discharged from theair outlet.

This invention is further characterized in that a filter is providedunder the dust collecting case.

This invention is further characterized in that the cyclonic separationcylinder takes in dirty air from the bottom of the cylinder and that thecyclonic separation cylinder has an air outlet that discharges clean airfrom the cylinder on the bottom of the cylinder, an opening tocommunicate with the dust collecting case placed close by the cylinderon the top of the cylinder, and a means of opening and closing thefilter to take out the accumulated dust from the dust collecting case.

This invention is further characterized in that the electric vacuumcleaner equipped with a cyclonic separation cylinder, that the cyclonicseparation cylinder takes in dirty air from the bottom of the cylinder,that the cyclonic separation cylinder has an air outlet that dischargesclean air from the cylinder on the bottom of the cylinder, and anopening to communicate with the dust collecting case placed close by thecylinder on the top of the cylinder, that the center axis of thecyclonic separation cylinder is a little slanted leftward or rightwardfrom the center of the electric vacuum cleaner (when viewed from thefront of the cleaner), and that the dust collecting case is a truncatedpyramid with its wider end down.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique perspective view of the appearance of an electricvacuum cleaner set which is an embodiment of the present invention.

FIG. 2 is an oblique perspective view of the main body of the electricvacuum cleaner of FIG. 1.

FIG. 3 is an oblique perspective view of the main body of the electricvacuum cleaner of FIG. 1 with the upper cover open.

FIG. 4 is an oblique perspective view of the main body of the electricvacuum cleaner of FIG. 1 with the upper cover open and without the dustcollecting case.

FIG. 5 is an oblique perspective view of the main body of the electricvacuum cleaner of FIG. 1 with the upper cover open and without the dustcollecting case and the cyclonic separation cylinder.

FIG. 6 is a top plan view of the main body of the electric vacuumcleaner without the upper casing and the upper cover.

FIG. 7 is airflow diagrams of the electric vacuum cleaner.

FIG. 8 is an oblique perspective view of the appearance of cyclonicseparation cylinder 104.

FIG. 9 is an oblique perspective view of the appearance of dustcollecting case 105.

FIG. 10 shows cross-sectional views taken along line A-A of FIG. 6.

FIG. 11 shows cross-sectional views of cyclonic separation cylinder 104including the air inlet port.

FIG. 12 shows cross-sectional views of cyclonic separation cylinder 104and dust collecting case 105 including communicating port 117.

FIG. 13 is a side view of dust collecting case 105 (viewed from theexhaust side).

FIG. 14 is an oblique perspective drawing of a combination of cyclonicseparation cylinder 104 and dust collecting case 105.

FIG. 15 is an oblique perspective view of the appearance of an uprightelectric vacuum cleaner set which is an embodiment of the presentinvention.

FIG. 16 is a side view of the upright electric vacuum cleaner set ofFIG. 15.

FIG. 17 is a vertical cross-sectional view of a combination of cyclonicseparation cylinder 404 and dust collecting case 405.

FIG. 18 shows a cross-sectional view of cyclonic separation cylinder 404and dust collecting case 405 including communicating port 417.

FIG. 19 is a vertical cross-sectional view of a combination of cyclonicseparation cylinder 404 and dust collecting case 405 which is anembodiment of the present invention.

BRIEF DESCRIPTION OF THE INVENTION Embodiment 1

Preferred embodiments of the present invention are described below withreference to the accompanying drawings. FIG. 1 is an oblique perspectiveview of the appearance of an electric vacuum cleaner set which is anembodiment of the present invention. FIG. 2 is an oblique perspectiveview of the main body of the electric vacuum cleaner of FIG. 1. FIG. 3is an oblique perspective view of the main body of the electric vacuumcleaner of FIG. 1 with the upper cover open. FIG. 4 is an obliqueperspective view of the main body of the electric vacuum cleaner of FIG.1 with the upper cover open and without the dust collecting case. FIG. 5is an oblique perspective view of the main body of the electric vacuumcleaner of FIG. 1 with the upper cover open and without the dustcollecting case and the cyclonic separation cylinder. FIG. 6 is a topplan view of the main body of the electric vacuum cleaner without theupper casing and the upper cover. FIG. 7 is airflow diagrams in the mainbody of the electric vacuum cleaner.

In this embodiment, the electric vacuum cleaner set comprises cleanerbody 1, hose 2, tube 3 with an operation panel, extension tube 4, andcleaner head (or floor nozzle) 5 as shown in FIG. 1. For use, the tube 3with an operation panel is connected to the cleaner body 1 with the hose2. The floor nozzle 5 is connected to the tube 3 with the extension tube4.

Cleaner body 1 takes in dirty air from floor nozzle 5 through extensiontube 4, tube 3 with an operation panel, and hose 2 by the suction forceof a built-in motor-driven blower (to be explained later), cleans theair in the cyclonic separation type dust collector (to be explainedlater, and discharges the clean air to the outside of the cleaner.

Referring to FIG. 2 to FIG. 6, cleaner body 1 detachably mounts acyclonic separation cylinder 104 and dust collecting case 105 betweenlower casing 101 and upper cover 102 and contains second auxiliaryfilter 112, motor-driven blower 107, and cord reel assembly 110 betweenlower casing and upper cover 102.

Referring to FIG. 7 (a), cleaner body 1 takes dirty air from hose 2 intocyclonic separation cylinder 104 though air inlet port 115, swirls upthe air therein to centrifugally separate dust from the air and carrythe dust into dust collecting case 105 through communicating port 117 onthe upper part of the cyclonic separation cylinder, and sends the cleanair from cyclonic separation cylinder 104 to air passage 120 providedunder cyclonic separation cylinder 104 through inner cylinder 131. Thedirty air carried into the dust collecting case 105 is filtered by firstauxiliary filter 106. The filtered air is sucked into motor-drivenblower 107 through communicating port 146 (behind first auxiliary filter106) and second auxiliary filter 112. At the same time, the clean airpassing through cyclonic separation cylinder 104 is also sucked into themotor-driven blower. The air blown out from motor-driven blower 107 isfiltered by filter 108. One part of the filtered air is discharged tothe outside through an air passage (not shown) and the other part of theair is sent to cord reel assembly 110 to cool it before being sent outto the outside.

Lower casing 101 is equipped with a guiding wheel (not shown) and wheels208 for facilitating movement of the cleaner body 1 across a floor.Lower casing 101 also has cyclonic separation cylinder 104 and dustcollecting case 105 that are detachably mounted in parallel. Secondauxiliary filter 112 is also mounted in parallel with them on lowercasing 101.

Upper cover 102 pivotally mounted on the upper rear part of the uppercasing 150 is energized to make air inlet port 115 of cyclonicseparation cylinder 104 hermetically contact with hose connection port116 and communicating port 117 of cyclonic separation cylinder 104hermetically contact with upper opening 118 of dust collecting case 105when the upper cover is closed. Upper cover 102 is also energized tomake air passage 120 under cyclonic separation cylinder 104 hermeticallycontact with air passage 165 under dust collecting case 105 and to makea space air tight between air outlet 146 of the cyclonic separator andfilter casing 113 of second auxiliary filter 112. The axis of cyclonicseparation cylinder 104 is vertical to the lower case but can beslanted.

Dust collecting case 105 provides pull-out handle 123 so that the usermay pull out dust collecting case 105 for disposal of accumulated dust.The dust in dust collecting case 105 can be dumped by opening firstauxiliary filter 106 in dust collecting case 105. As first auxiliaryfilter 106 is provided on the bottom of dust collecting case 105, theuser can easily dump the accumulated dust without turning user's hand.

When the inside of cyclonic separation cylinder 104 becomes dirty, theuser can pull out cyclonic separation cylinder 104 by pull-out handle125 on the cylinder and clean the inside of the cyclonic separationcylinder 104.

The inner surfaces of cyclonic separation cylinder 104 and dustcollecting case 105 are coated with UV curing clear resin to protect thesurfaces against damages due to collision and scratches by dustparticles that flow into cyclonic separation cylinder 104 and dustcollecting case 105 and against contamination. This coat increases thefriction resistance and contamination resistance of the surfaces.Therefore, even when outer cylinder 135 of cyclonic separation cylinder104 and dust collecting case 105 are made of clear plastic materials,the quantity of dust in the cylinder and the case can be easilyrecognized by eyes.

It is also preferable to mold cyclonic separation cylinder 104 and dustcollecting case 105 with antistatic resin materials or to coat surfacesthereof with antistatic materials. This prevents static cling of dustparticles to the surfaces of cyclonic separation cylinder 104 and dustcollecting case 105 and they need not be cleaned so often.

Referring to FIG. 6, the layout of components of cleaner body 1 will beexplained below.

FIG. 6 is a top plan view of the main body of the electric vacuumcleaner without upper casing 150 and the upper cover 102.

Hose connection port 116 is located in the center of the width ofcleaner body 1 (when viewed from the top). The center axis of cyclonicseparation cylinder 104 is moved a little from the center of the widthof cleaner body 1. Further, air inlet port 115 to introduce the dirtyair approximately tangentially to cyclonic separation cylinder 104 isarranged in alignment with hose connection port 116.

Dust collecting case 105 is placed opposite to the center axis ofcyclonic separation cylinder 104 (in relation to the center of the widthof cleaner body 1). Similarly motor-driven blower 107 is placed oppositeto the center axis of cyclonic separation cylinder 104 (in relation tothe center of the width of cleaner body 1). Second auxiliary filter 112is provided in front of the motor-driven blower. Cord reel assembly 110is provided next to motor-driven blower in the side where the centeraxis of cyclonic separation cylinder 104 exists (in relation to thecenter of the width of cleaner body 1).

This disposition can make the cleaner body shorter, smaller, and lessweighted.

Further, this disposition requires no bending at the air inlet port ofcyclonic separation cylinder 104 and can reduce a loss.

Below will be explained cyclonic separation cylinder 104 and dustcollecting case 105 in detail with reference to FIG. 8 to FIG. 13. FIG.8 is an oblique perspective view of the appearance of cyclonicseparation cylinder 104. FIG. 9 is an oblique perspective view ofappearance of dust collecting case 105. FIG. 10 (a) shows across-sectional view taken along line A-A of FIG. 6. FIG. 11 (a) shows across-sectional view of cyclonic separation cylinder 104 including theair inlet port. FIG. 12 (a) shows a cross-sectional view of cyclonicseparation cylinder 104 and dust collecting case 105 includingcommunicating port 117. FIG. 13 (a) is a side view of dust collectingcase 105 (viewed from the exhaust side).

Outer cylinder 135 of cyclonic separation cylinder 104 has air inletport 115 on the lower part of the cylinder (below the center of thelongitudinal center axis of the cylinder) to introduce dirty airapproximately tangentially to cyclonic separation cylinder 104 which isapproximately cylindrical.

Cyclonic separation cylinder 104 also has communicating port 117 on theupper part of the cylinder to introduce dirty air into dust collectingcase 105. Cyclonic separation cylinder 104 has inner cylinder 131 on thebottom of the cyclonic separation cylinder 104 which communicates withlower communicating passage 120. Inner cylinder 131 comprises partitionwall 132 and cylindrical member 134 with which net filter 133 made ofplastic fiber is formed in a body by insert-mounting. As shown in FIG.10 (a), net filter 133 can be formed singly on the top of thecylindrical member or together with the side of the cylindrical member.When net filter 133 is treated with antistatic agent, dust on net filter133 can be easily knocked off.

Cyclonic separation cylinder 104 comprises outer cylinder 135, innercylinder 131, and a member that forms air passage 120. These componentsare respectively detachable and combined together to prevent air anddirt leaking there from. It is preferable to place a sealing memberbetween the components that are combined. For cleaning of cyclonicseparation cylinder 104, outer cylinder 135, inner cylinder 131, and amember that forms air passage 120 are separated individually.

Dust collecting case 105 has upper opening 118 in alignment withcommunicating port 117 of cyclonic separation cylinder 104. Upperopening 118 and communicating port 117 are linked in an air-tightmanner. Dust collecting case 105 also has filter frame 140 with firstauxiliary filter 106 on the exhaust side of the case. The frame has itssides open and can rotate around the lower side of the frame. Whenclosed, filter frame 140 is hermetically in close contact with case 141of dust collecting case 105.

For dust disposal, the user takes out dust collecting case 105 bypull-out handle 123 thereof, pulls lever 142 of a clamp means that locksfilter frame 140 to open the frame, and dumps dust collecting case 105.The user can take out first auxiliary filter 106 from filter frame 140to wash thereof.

Auxiliary filter 106 is preferably made of foamed washable plasticmaterial such as sponge or washable nonwoven cloth.

When first auxiliary filter 106 and second auxiliary filter 112 aretreated with antistatic agent, dust on the filters can be easily knockedoff.

Dust collecting case 105 has a combination of air passage 145 andcommunicating port 146 thereunder. Therefore, dust collecting case 105comprises case 141, air passage 145, and communicating port 146 underfilter frame 140. They are linked hermetically in close contact witheach other.

Filter frame 140 is also hermetically in close contact with filtercasing 113 that holds second auxiliary filter 112 in front ofmotor-driven blower 107. To assure their airtightness, an elasticsealing member is preferably placed between the filter frame and thefilter case.

When motor-driven blower 107 is turned on, cleaner body 1 of the aboveconfiguration takes in dirty air from air inlet port 115 of cyclonicseparation cylinder 104 into the cylinder by the suction force, swirlsup the dirty air to separate dust centrifugally and deliver theseparated dust into dust collecting case 105, and sucks the clean airfrom inner cylinder 131 of cyclonic separation cylinder 104 into airmessage 120 through net filter 133. This net filter functions to capturelint.

The air from air passage 120 is sent to second auxiliary filter 112through air passage 145 and communicating port 146.

The dirty air coming from cyclonic separation cylinder 104 flows intodust collecting case 105 through upper opening 118 that communicateswith communicating port 117. The dust in the air is stopped by firstauxiliary filter 106 and accumulates before the filter. The air passingthrough the auxiliary filter flows toward the second auxiliary filter.

The dust capturing performance of first auxiliary filter 106 isdependent upon the characteristics of the filter material and isexpected to catch dust particles of some microns big. If the dustcapturing performance is increased, the filter may be blocked quickly.Therefore, the dust capturing performance must be determined consideringthe whole dust capturing performance of the electric vacuum cleaner.

As almost all dust brought into cleaner body 1 together with air isaccumulated in dust collecting case 105, only dust collecting case 105can be taken out from cleaner body 1 to dump it. It is preferable toperform this dumping before dust overflows dust collecting case 105. Toknow the timing to dump dust collecting case 105, dust indicator 155 isprovided on dust collecting case 105 opposite to upper opening 118 asshown in FIG. 9. The user can judge the dumping timing by thisindicator. The dust indicator is neither vertical nor horizontal, but itis slanted as the dust accumulates thinner near upper opening 118.

Referring to FIG. 7 (a), this embodiment divides the airflow into two incleaner body 1. These air flows cause a pressure difference in dustcollecting case 105 and this pressure difference always presses the dustin dust collecting case 105. This pressure difference becomes greater asmore dust accumulates in dust collecting case 105. Further the dust iscompressed more strongly as the dust becomes more. This mechanism allowsmore dust to be accumulated in dust collecting case 105 and consequentlyreduces a dust dumping frequency.

Further, as this mechanism makes the air flow going out of cyclonicseparation cylinder 104 less than the air flow when no air flows intodust collecting case 105, the resistance of cyclonic separation cylinder104 can be reduced and the vacuum cleaner can have a greater suctionpower.

As more dust accumulates in dust collecting case 105, the resistance ofair passing through dust collecting case 105 increases and the flow rateof air in the case reduces. This has an effect to reduce bad smells fromthe dust when the dust contains materials that give out bad smells.Therefore, less bad smells are exhausted out of the cleaner body.

It is also possible to easily clean air passage 145 and communicatingport 146 (when they are dirty) with dust collecting case 105 removed.

Further, as cyclonic separation cylinder 104 has air inlet port 115 andinner cylinder 131 on the lower part thereof, the communicating port canbe provided on the upper part. This prevents dust from leaking fromcyclonic separation cylinder 104.

Further as dust collecting case 105 is provided by cyclonic separationcylinder 104, the longitudinal length of cyclonic separation cylinder104 can be made greater without increasing the height of cleaner body 1.This feature can increase the capacity of separating dust by swirling.

Further, heavy dust particles such as rings that are not affected by afluid force are apt to stay in cyclonic separation cylinder 104. Theuser can easily take out such dust particles from air inlet port 115just by taking up cyclonic separation cylinder 104 by pull-out handle125 and tilting the cylinder.

As shown in FIG. 14, cyclonic separation cylinder 104 and dustcollecting case 105 can be formed in a body. This unit is heavy and notso convenient in handling, but the connection between cyclonicseparation cylinder 104 and dust collecting case 105 and the connectionbetween air passage 120 and air passage 145 are formed in a body andmade air-tight perfectly. This can suppress pressure loss due to leakageand increase the suction power.

It is also possible to form air passage 120, air passage 145, andcommunicating port 146 with a member of another material in closecontact with lower casing 101. This mechanism does not facilitatecleaning of air passage 145 when it becomes dirty, but can reduce thenumber of places to be hermetically sealed. Further, this mechanism alsofacilitates sealing in a vertical direction only.

Embodiment 2

A second preferred embodiment of the present invention is describedbelow with reference to FIG. 7 (b), FIG. 8, FIG. 9, FIG. 10 (b), FIG. 11(b), FIG. 12 (b), FIG. 13 (b), FIG. 15, and FIG. 16.

Referring to FIG. 7 (b), cleaner body 1 takes dirty air from hose 2 intocyclonic separation cylinder 104 though air inlet port 115, swirls upthe air therein to centrifugally separate dust from the air and carrythe dust into dust collecting case 105 through communicating port 117 onthe upper part of the cyclonic separation cylinder, and sends the cleanair from cyclonic separation cylinder 104 to air passage 120 providedunder cyclonic separation cylinder 104 through inner cylinder 131. Thedirty air carried into the dust collecting case 105 is filtered by firstauxiliary filter 106.

The filtered air is sucked into motor-driven blower 107 through airoutlet 146 of the cyclonic separator (behind first auxiliary filter 106)and second auxiliary filter 112. At the same time, the clean air passingthrough cyclonic separation cylinder 104 is also sucked into themotor-driven blower through the air outlet 120, and air passage 145together with the clean air from dust collecting case 105. The air blownout from motor-driven blower 107 is filtered by filter 108. One part ofthe filtered air is discharged to the outside through an air passage(not shown) and the other part of the air is sent to cord reel assembly110 to cool it before being sent out to the outside. FIG. 8 is anoblique perspective view of the appearance of cyclonic separationcylinder 104. FIG. 9 is an oblique perspective view of the appearance ofdust collecting case 105. FIG. 10 (b) shows a cross-sectional view takenalong line A-A of FIG. 6. FIG. 11 (b) shows a cross-sectional view ofcyclonic separation cylinder 104 including the air inlet port. FIG. 12(b) shows a cross-sectional view of cyclonic separation cylinder 104 anddust collecting case 105 including communicating port 117. FIG. 13 (b)is a side view of dust collecting case 105 (viewed from the exhaustside). Outer cylinder 135 of cyclonic separation cylinder 104 has airinlet port 115 on the lower part of the cylinder (below the center ofthe longitudinal center axis of the cylinder) to introduce dirty airapproximately tangentially to cyclonic separation cylinder 104 which isapproximately cylindrical.

Cyclonic separation cylinder 104 also has communicating port 117 on theupper part of the cylinder to introduce dirty air into dust collectingcase 105. Cyclonic separation cylinder 104 has inner cylinder 131 on thebottom of the cyclonic separation cylinder 104 which communicates withlower communicating passage 120. Inner cylinder 131 comprises partitionwall 132 and cylindrical member 134 with which net filter 133 made ofplastic fiber is formed in a body by insert-mounting. As shown in FIG.10 (b), net filter 133 can be formed on the wall of the cylindricalmember or on both of the top and the cylindrical member.

In this embodiment, the net filter 133 is not formed on the wholeperiphery of the wall of inner cylinder 131. Net filter 133 and theopening are not provided in a 90-degree area of the inner cylinder nearair inlet port 115. This prevents long dust particles such as hairs(sent from air inlet port 115) from directly hitting net filter 133,sticking into the net filter or being twined around with the net filter.

Similarly, this prevents sharp-pointed materials such as pins andneedles (sent from air inlet port 115) from directly hitting net filter133, breaking the net filter, and leaking.

Further, inner cylinder 131 requires a plurality of ribs 136 on theinner side of the cylinder to support the net filter because the netfilter receives a centripetal force.

When net filter 133 is treated with antistatic agent, dust on the netfilter can be easily knocked off and cleaned.

Outer cylinder 135 of cyclonic separation cylinder 104 has air inletport 115 on the lower part of the cylinder (below the center of thelongitudinal center axis of the cylinder) to introduce dirty air.Therefore, hose connection port 116 communicating with air inlet port115 can also be placed on the lower part of cyclonic separation cylinder104 (below the center of the longitudinal center axis of the cylinder).

As hose connection port 116 is provided on the lower part of cleanerbody 1, the cleaner body can be pulled around steadily by moving thetube with the operation panel 3 that is connected to the cleaner bodywith hose 2.

Further, hose connection port 116 can be provided on the lower part ofcleaner body 1 and need not be provided on upper cover 102. Therefore,it is possible to open the upper cover and take out dust collecting case105 and cyclonic separation cylinder 104 easily without disconnectingthe hose.

Cyclonic separation cylinder 104 comprises outer cylinder 135, innercylinder 131, and a member that forms air passage 120. These componentsare respectively detachable and combined together to prevent air anddirt leaking therefrom. It is preferable to place a sealing memberbetween the components that are combined. For cleaning of cyclonicseparation cylinder 104, outer cylinder 135, inner cylinder 131, and amember that forms air passage 120 are separated individually.

Dust collecting case 105 has upper opening 118 in alignment withcommunicating port 117 of cyclonic separation cylinder 104. Upperopening 118 and communicating port 117 are linked in an air-tightmanner. Dust collecting case 105 also has filter frame 140 with firstauxiliary filter 106 on the exhaust side of the case.

The frame has its sides open and can rotate around the lower side of theframe. When closed, filter frame 140 is hermetically in close contactwith case 141 of dust collecting case 105. For dust disposal, the usertakes out dust collecting case 105 by pull-out handle 123 thereof,pushes lever 142 of a clamp means that locks filter frame 140 to openthe frame, and dumps dust collecting case 105. As dust collecting case105 is wider towards the bottom, it is very easy to empty dustcollecting case 105 completely.

The user can take out first auxiliary filter 106 from filter frame 140to wash thereof.

Auxiliary filter 106 is preferably made of foamed washable plasticmaterial such as sponge or washable nonwoven cloth.

When first auxiliary filter 106 and second auxiliary filter 112 aretreated with antistatic agent, dust on the filters can be easily knockedoff.

Dust collecting case 105 has a combination of air passage 145 and airoutlet 146 of the cyclonic separator thereunder. Therefore, dustcollecting case 105 comprises case 141, air passage 145, andcommunicating port 146 under filter frame 140. They are linkedhermetically in close contact with each other.

Filter frame 140 is also hermetically in close contact with filtercasing 113 that holds second auxiliary filter 112 in front ofmotor-driven blower 107. To assure their airtightness, an elasticsealing member is preferably placed between the filter frame and thefilter case.

When motor-driven blower 107 is turned on, cleaner body 1 of the aboveconfiguration takes in dirty air from air inlet port 115 of cyclonicseparation cylinder 104 into the cylinder by the suction force, swirlsup the dirty air to separate dust centrifugally and deliver theseparated dust into dust collecting case 105, and sucks the clean airfrom inner cylinder 131 of cyclonic separation cylinder 104 into airpassage 120 through net filter 133.

This net filter functions to capture lint, paper dust, and so on.

The air from air passage 120 is sent to second auxiliary filter 112through air passage 145 and communicating port 146.

The dirty air coming from cyclonic separation cylinder 104 flows intodust collecting case 105 through upper opening 118 that communicateswith communicating port 117. The dust in the air is stopped by firstauxiliary filter 106 and accumulates before the filter. The air passingthrough the auxiliary filter flows toward the second auxiliary filter.

The dust capturing performance of first auxiliary filter 106 isdependent upon the characteristics of the filter material and isexpected to catch dust particles of some microns big. If the dustcapturing performance is increased, the filter may be blocked quickly.Therefore, the dust capturing performance must be determined consideringthe whole dust capturing performance of the electric vacuum cleaner.

As almost all dust brought into cleaner body 1 together with air isaccumulated in dust collecting case 105, only dust collecting case 105can be taken out from cleaner body 1 to dump it. It is preferable toperform this dumping before dust overflows dust collecting case 105. Toknow the timing to dump dust collecting case 105, dust indicator 155 isprovided on dust collecting case 105 opposite to upper opening 118 asshown in FIG. 9. The user can judge the dumping timing by thisindicator. The dust indicator is neither vertical nor horizontal, but itis slanted as the dust accumulates thinner near upper opening 118.

Referring to FIG. 7 (b), this embodiment divides the airflow into two incleaner body 1. These air flows cause a pressure difference in dustcollecting case 105 and this pressure difference always presses the dustin dust collecting case 105. This pressure difference becomes greater asmore dust accumulates in dust collecting case 105. Further the dust iscompressed more strongly as the dust becomes more.

As first auxiliary filter 106 is provided on the lower part of dustcollecting case 105, the dust in dust collecting case 105 is compressedby its weight. This mechanism allows more dust to be accumulated in dustcollecting case 105 and consequently reduces a dust dumping frequency.

The dust in dust collecting case 105 accumulates in layers in front offirst auxiliary filter 106, catching up fine dust in the layers. Thishas an effect of preventing fine dust from rising up when theaccumulated dust is disposed of.

Further, as this mechanism makes the air flow going out of cyclonicseparation cylinder 104 through air outlet 120 less than the air flowwhen no air flows into dust collecting case 105, the resistance ofcyclonic separation cylinder 104 can be reduced and the vacuum cleanercan have a greater suction power.

Dirty air introduced into cyclonic separation cylinder 104 though airinlet port 115 is forced to swirl therein. Dust particles in the dirtyair are centrifugally separated from the air, lifted up in cyclonicseparation cylinder 104, and delivered into dust collecting case 105.

Because of the air flow passing through first auxiliary filter 106 ofdust collecting case 105 from cyclonic separation cylinder 104, dustthat is centrifugally separated in cyclonic separation cylinder 104 isapt to go into dust collecting case 105 and immediately separated indust collecting case 105. This increases the dust collection efficiency.

The dust that is centrifugally separated in cyclonic separation cylinder104 and delivered to dust collecting case 105 will not go back tocyclonic separation cylinder 104. This prevents re-flow of dust fromdust collecting case 105 and increase the dust collection efficiency.

As dust is captured by net filter 133 of inner cylinder 131, the flowrate of clean air from air outlet 120 of cyclonic separation cylinder104 reduces. This increases the flow rate of air that is filtered byfirst auxiliary filter 106 from air outlet 144 of dust collecting case105. Therefore, the dust on the net filter in dust collecting case 105is apt to be delivered to dust collecting case 105.

In this embodiment, the cross-section of air outlet 144 that flows airfrom first auxiliary filter 106 of dust collecting case 105 is madegreater than the cross-section of air outlet 120 that flows the cleanare from cyclonic separation cylinder 105. This makes the cross-sectionof the first auxiliary filter and reduce the flow rate of air passingthrough the first auxiliary filter. This can reduce the quantity of dustthat passes through the first auxiliary filter. Further, this can reducethe pressure loss of air that flows through first auxiliary filter 106and consequently increases the suction power of the vacuum cleaner.

Here, it is possible to prevent dust from being caught by downstream end119 of communicating port 117 of cyclonic separation cylinder 104 bycurving the downstream end or applying a smooth slippery material (of alow friction coefficient) to the downstream end. When the upper side ofdownstream end 119 is tilted towards first air outlet 144 that is theoutlet of air from dust collecting case 105 (or when the upper part ofthe opening of communicating port 117 is made wider), it is possiblethat dust particles caught at downstream end 119 of communicating port117 are moved up in the communicating port and ripped away by the airflowing from cyclonic separation cylinder 104 to dust collecting case105.

As more dust accumulates in dust collecting case 105, the resistance ofair passing through dust collecting case 105 increases and the flow rateof air in the case reduces. This has an effect to reduce bad smells fromthe dust when the dust contains materials that give out bad smells.Therefore, less bad smells are exhausted out of the cleaner body.

Air passage 145 and cyclonic separator air outlet 146 (when dirty) canbe cleaned with dust collecting case 105 removed.

Further, as air inlet port 115 and inner cylinder 131 are provided onthe lower part of cyclonic separation cylinder 104, communicating port117 of cyclonic separation cylinder 104 and upper opening 118 of dustcollecting case 105 can be provided on the upper part thereof. Dustcoming into dust collecting case 105 goes down by gravity and will notgo back to cyclonic separation cylinder 104.

Further, upper opening 118 of dust collecting case 105 is provided onthe upstream side of dust collecting case 105. When cleaner body 1stands upright for storage, upper opening 118 of dust collecting case105 comes over dust collecting case 105. Therefore, dust in dustcollecting case 105 will never fall back into cyclonic separationcylinder 104.

Further as dust collecting case 105 is provided by cyclonic separationcylinder 104, the longitudinal length of cyclonic separation cylinder104 can be made greater without increasing the height of cleaner body 1.This feature can increase the capacity of separating dust by swirling.

A valve can be provided near air inlet port 115 to close the air inletport when motor-driven blower 107 stops and to close a space betweeninner cylinder 131 and part of the inner wall of outer cylinder 135 incyclonic separation cylinder 104.

Heavy dust particles such as rings that are not affected by a fluidforce will come into collision with the valve and stop swirling. Thisprotects the inner wall of outer cylinder 185 against damages bycollision of dust particles. This valve can prevent leaking of dust whenmotor-driven blower 107 is turned off and cyclonic separation cylinder104 is taken out from the cleaner body.

As heavy dust particles such as rings that are not affected by a fluidforce will not be carried into dust collecting case 105 from cyclonicseparation cylinder 104, first auxiliary filter 106 of dust collectingcase 105 cannot be broken and will not let any dust pass through.

As shown in FIG. 14, cyclonic separation cylinder 104 and dustcollecting case 105 can be formed in a body. This unit is heavy and notso convenient in handling, but the connection between cyclonicseparation cylinder 104 and dust collecting case 105 and the connectionbetween air passage 120 and air passage 145 are formed in a body andmade air-tight perfectly. This can suppress pressure loss due toleakage, increase the suction power, and suppress leaking of dust.

It is also possible to form air passage 120, air passage 145, andcommunicating port 146 with a member of another material in closecontact with lower casing 101. This mechanism does not facilitatecleaning of air passage 145 when it becomes dirty, but can reduce thenumber of places to be hermetically sealed. Further, this mechanism alsofacilitates sealing in a vertical direction only and increase thesuction power.

Embodiment 3

A third preferred embodiment of the present invention is described belowwith reference to FIG. 15 to FIG. 18. FIG. 15 is an oblique perspectiveview of the appearance of an upright electric vacuum cleaner set whichis an embodiment of the present invention.

FIG. 16 is a side view of the upright electric vacuum cleaner set ofFIG. 15. This is a partial sectional view of the vacuum cleaner toexplain airflow thereof. FIG. 17 is a vertical cross-sectional view of acombination of cyclonic separation cylinder 404 and dust collecting case405. FIG. 18 shows a cross-sectional view of cyclonic separationcylinder 404 and dust collecting case 405 including communicating port417.

Vacuum cleaner 301 has a floor cleaning head 305 which is open to thefloor and rotatable in a predetermined angle range. The floor cleaninghead contains a floor-contacting rotating brush member 306. Vacuumcleaner 301 detachably contains dust collector 460 which rotatablycomprises cyclonic separation cylinder 404, dust collecting case 405,and dust collector lid 461 thereunder. Motor-driven blower is locatedabove floor cleaning head 305 and below dust collector 460 (undercleaner body 301) to drive brush member 306 in floor cleaning head 305and the blower by the rotation of the rotary shaft of the motor-drivenblower. The suction force of the motor-driven blower introduces dirtyair from floor cleaning head 305, carries it to dust collecting case 405by cyclonic separation cylinder 404 through joint tube 304 and hose 302.Handle 303 is provided on cleaner body 301 to move the electric vacuumcleaner across the floor.

Cleaner body 301 takes dirty air from hose 302 into cyclonic separationcylinder 404 though air inlet port 415, swirls up the air therein tocentrifugally separate dust from the air and carry the dust into dustcollecting case 405 through communicating port 417 on the upper part ofthe cyclonic separation cylinder, and sends the clean air from cyclonicseparation cylinder 404 to air passage 420 provided under cyclonicseparation cylinder 404 through inner cylinder 431. The dirty aircarried into the dust collecting case 405 is filtered by first auxiliaryfilter 406. The filtered air is sucked into the motor-driven blowerthrough air outlet 446 of the cyclonic separator (behind first auxiliaryfilter 406) and second auxiliary filter 412.

At the same time, the clean air passing through cyclonic separationcylinder 404 is also sucked into the motor-driven blower through the airoutlet 420, and air passage 445 together with the clean air from dustcollecting case 405. The air blown out from the motor-driven blower isfiltered and discharged to the outside of the cleaner body.

The components are so energized that air inlet port 415 of cyclonicseparation cylinder 404 may be in airtight contact with hose connectionport 416, that air outlet 420 under cyclonic separation cylinder 404 maybe in airtight contact with air passage 445, and that outlet 446 ofcyclonic separation cylinder 104 may be in airtight contact with filtercasing 413 containing second auxiliary filter 412.

An elastic material is provided between dust collector lid 461 and eachof cyclonic separation cylinder 404 and dust collecting case 405 so thatthey may be in airtight contact with each other when a vertical force isapplied thereto. Further, elastic sealing member 450 is provided betweenthe inlet of the motor-driven blower and cleaner body 301 to make themin airtight contact with each other. The above airtightness becomesperfect when a vertical force is applied thereto. In other words, thisairtightness is assured when the user pushes down dust collector 460against vacuum cleaner 301 and fastens the dust collector down to thecleaner body with fasteners (not shown). This prevents leaking of dustand air. Elastic sealing member 450 also works to support secondauxiliary filter 412 on dust collector lid 461

The axis of cyclonic separation cylinder 404 is not vertical but slanteda little. With this, the longitudinal length of cyclonic separationcylinder 404 can be made greater and the dust collection performance canbe increased without increasing the height of cleaner body 301.

The user can take out cyclonic separation cylinder 404 and dustcollecting case 405 from cleaner body 301 by pull-out handle 423.

First auxiliary filter 406 and auxiliary filter casing 440 are providedon the exhaust side of dust collecting case 405 and net filter 406 a isinsert-mounted on the opening of auxiliary filter casing 440.

The back of first auxiliary filter 406 is supported by dust collectorlid 461 having a filter support that comprises a plurality ofrectangular openings filled with filter 406 b.

The dust collector lid 461 also makes the edges of first auxiliaryfilter 406 and auxiliary filter casing 440 airtight.

Dust collector lid 461 is provided under first auxiliary filter 406 andair outlet 420 of the cyclonic separation cylinder. The whole inside ofthe dust collector lid 461 is filled with second auxiliary filter 412supported by filter frame 413.

First auxiliary filter 406 is preferably made of sponge or othermaterial that can capture a lot of dust. Washable sponge materials madefrom ether are more preferable in handling. When treated by antistaticagent, net filter 406 a before first auxiliary filter 406 can knock offdust easily and make dust disposal easier. Filter 406 attached to dustcollector lid 461 can prevent leaking of dust from dust collecting case405 when it is of a nonwoven or net filter type. For easy handling,filter 406 made of a nonwoven material or the like is insert-mountedwith dust collector lid 461 in a body.

Preferably, second auxiliary filter 412 can be a pleated nonwovenfilter. As this filter supports the whole lower part of cyclonic dustcollector 460, the filtering area can be made greater and consequentlythe air flow resistance can be reduced. Further, as the air can bedirectly flown to the motor-driven blower, the air flow resistance canbe reduced and as the result, the suction power can be increased.

First auxiliary filter 406 is provided on the bottom of dust collectingcase 405 far away from communicating port 417. In other words,communicating port 417 is on the upper right corner of FIG. 17 and firstauxiliary filter 406 is on the lower left corner of FIG. 17. The dirtyair passing through communicating port 417 is apt to flow to the lowerleft part as it is sucked from the side of first auxiliary filter 406.Dust in the dirty air is accumulated and compressed from the lower leftside of dust collecting case 405. Therefore, more dust can beaccumulated in dust collecting case 405. Further, as first auxiliaryfilter 406 is provided on the bottom of dust collecting case 405, dustin the dust collecting case is compressed by its weight and more dustcan be accumulated in the dust collecting case. Consequently, thisreduces a dust dumping frequency. Further this mechanism has a featureof preventing fine dust from rising up when the accumulated dust isdisposed of as fine particles such as lint, sands, and soil in dust arecaught up in dust layers.

When dust collector 460 is mounted on cleaner body 401, cyclonicseparation cylinder 404 is behind dust collecting case 405 (when viewedfrom the front of the electric vacuum cleaner).

As communicating port 417 and upper opening 418 of dust collecting case405 are provided before the cyclonic separation cylinder, a dustindicator line (not shown) can be marked on the front side opposite toupper opening 418 so that the user can know proper timing to dump thedust. The dust indicator line is marked aslant because the dustaccumulates thinner near upper opening 418.

For dust disposal, dust collector lid 461 is opened. As dust collectingcase 405 is wider towards the bottom, it is very easy to empty dustcollecting case 405 completely and almost no dust will remain in dustcollecting case 405.

When filters are clogged, the user takes steps of opening dust collectorlid 461 and auxiliary filter casing 440, taking out the first auxiliaryfilter, wash it, drying it by air seasoning, then remounting the dryfilter. To clean second auxiliary filter 412, the user takes steps oftaking the second auxiliary filter together with auxiliary filter frame413, wash them, drying them by air seasoning, then remounting the dryfilter together with the filter frame.

It is also possible to mount inner cylinder 431 on dust collector lid461 and make it open together when dust collector lid 461 is closed fordisposal of dust. This mechanism facilitates disposal of dust thatoverloaded from dust collecting case 405 into cyclonic separationcylinder 404 when dust collecting case 405 is overloaded.

The inner surfaces of cyclonic separation cylinder 404 and dustcollecting case 405 are coated with UV curing clear resin, to protectthe surfaces against damages due to collision and scratches by dustparticles that flow into cyclonic separation cylinder 404 and dustcollecting case 405 and against contamination. This coat increases thefriction resistance and contamination resistance of the surfaces.Therefore, even when outer cylinder 435 of cyclonic separation cylinder404 and dust collecting case 405 are made of clear plastic materials,the quantity of dust in the cylinder and the case can be easilyrecognized by eyes.

When cyclonic separation cylinder 404 and dust collecting case 405 aremolded with antistatic materials or when surfaces thereof are coatedwith antistatic materials, the cyclonic separation cylinder and the dustcollecting case become less contaminated and consequently, they need notbe cleaned so frequently.

Outer cylinder 435 of cyclonic separation cylinder 404 has air inletport 415 on the lower part of the cylinder (below the center of thelongitudinal center axis of the cylinder) to introduce dirty airapproximately tangentially to cyclonic separation cylinder 404 which isapproximately cylindrical. Therefore, hose connection port 416 can beprovided below cleaner body 301, which can make hose 302 shorter. Thiscan also reduce frictional losses and so on.

Communicating port 417 is provided on the upper part (above the center)of cyclonic separation cylinder 404 to introduce dirty air into dustcollecting case 405. Inner cylinder 431 is provided below cyclonicseparation cylinder 404 and communicates with air outlet 420 thereunder.As air outlet 420 can be provided below the cyclonic separationcylinder, the air passage towards the motor-driven blower can be madeshorter. This configuration can make cleaner body 301 shorter,compactor, and less weight. This also has an effect to reduce frictionallosses.

Inner cylinder 431 comprises partition wall 432 and cylindrical member434 with which net filter 433 made of plastic fiber is formed in a bodyby insert-mounting. Net filter 433 can be formed on the wall of thecylindrical member or on the top of the cylindrical member. In thisembodiment, the net filter 433 is not formed on the whole periphery ofthe wall of inner cylinder 431. Net filter 433 and the opening are notprovided in a 90-degree area of the inner cylinder near air inlet port415. This prevents long dust particles such as hairs (sent from airinlet port 415) from directly hitting net filter 433, sticking into thenet filter or being twined around with the net filter. Similarly, whenair inlet port 415 is curved upward, this prevents sharp-pointedmaterials such as pins and needles (sent from air inlet port 415) fromdirectly hitting net filter 433, breaking the net filter, and leaking.Further, a plurality of ribs are provided on the inner side of thecylinder to support the net filter because net filter 433 receives acentripetal force.

When net filter 433 is treated with antistatic agent, dust on the netfilter can be easily knocked off and cleaned.

Embodiment 4

A fourth preferred embodiment of the present invention is describedbelow with reference to FIG. 19.

FIG. 19 is a vertical cross-sectional view of a cyclonic dust collector560 comprising a cyclonic separation cylinder 504 and a dust collectingcase 505 which is an embodiment of the present invention.

The cyclonic separation section comprises cyclonic separation cylinder504 which is approximately cylindrical, dust collecting case 505, andfilter casing 513 which is under the dust collecting case. This cyclonicseparation section is mounted on the cleaner body detachably. Themotor-driven blower is provided under this cyclonic separation section.Air inlet port 515 is formed in a body on cyclonic separation cylinder504 to introduce air into cyclonic separation cylinder 504 along theperiphery of the cylinder. Air inlet port 515 is circular in the sectionbut can be rectangular with rounded corners.

Dust collecting case 505 is provided in a body under cyclonic separationcylinder 504. The inner cross-section of the cyclonic separation sectionbecomes greater as you go from cyclonic separation cylinder 504 to dustcollecting case 505. In other words, the cyclonic separation sectionbecomes wider as you go downward. The dust collecting case 505 has acircular cross-section but can have a rectangular cross-section withrounded corners.

Inner cylinder 531 comprises cylindrical member 534 having a circularcross-section, downward-curved partitioning wall which separatescyclonic separation cylinder 504 from dust collecting case 504 and anopening on the upper part. Net filter 533 is formed in a body on theopening by insert-molding.

The upper end of inner cylinder 531 is fit to cylinder-fixing rib 531which is formed in a body on cyclonic separation cylinder 504. This ribhas a mechanism (not shown) to fasten the inner cylinder in an air-tightstate when the inner cylinder is fit into the rib and turned. The lowerpart of inner cylinder 531 has air outlet 520 to discharge air from thecyclonic separation cylinder 504.

The cyclonic separation section has dust collector lid 561 comprisingfilter casing 513 and others on its bottom.

The dust collector lid 561 has first auxiliary filter 506 and filterframe 540 that covers the first auxiliary filter on the upper part ofthe dust collector lid 561. The filter frame contains net filter 406 ain a body by insert-molding. Filter frame 540 has an approximatelycircular section in its center.

The dust collector lid 561 contains filter casing 513 which holds secondauxiliary filter 512. The filter casing 513 is in close contact withdust collecting case 505. The upper part of filter casing 513 comprisesa partitioning wall having a lot of openings and a cylindrical sectionto be fit to inner cylinder 531 in the center thereof. The partitioningwall contains net filter 406 a in a body by insert-molding. Thepartitioning wall supports the first auxiliary filter and filter frame540 is detachably mounted thereon. Dust collector lid 561 has, on itsbottom edge, an elastic member in close contact with the opening at theentrance of the motor-driven blower. This elastic member also works tohold second auxiliary filter 512.

When the cyclonic separation section is mounted on the cleaner body, thedust collector lid 561 is strongly pressed by the partitioning wallhaving the opening in the entrance of the motor-driven blower.

The air-tightness between dust collector lid 561 and each of dustcollecting case 505 and inner cylinder 531 is assured by means of anelastic sealing member therebetween when a vertical force is applied.This can prevent leaking of dust and air.

Next will be explained how air and dust flow through the electric vacuumcleaner of this embodiment.

Dirty air is introduced from air inlet port 515 into cyclonic separationcylinder 504, and made to swirl there to centrifugally separate dustfrom the air. The separated dust is delivered into dust collecting case505 through communicating port 517. The clean air from cyclonicseparation cylinder 504 is sucked into inner cylinder 531 through netfilter 533 on the upper part of inner cylinder 531 and sent toward dustcollector lid 561 through air outlet 520 provided on the bottom ofcyclonic separation cylinder 504.

Further part of air is sucked into dust collecting case 505 throughcommunicating port 517 formed outside of partitioning wall 532 of innercylinder 531 and de-dusted by first auxiliary filter 506. The clean airfrom dust collecting case 505 passes through net filter 506 b underfirst auxiliary filter 506, and flows into the second auxiliary filtertogether with air from the cylindrical member formed in the center offilter casing 513. These two air passages forms outlet 546 of the dustseparation cyclone. The clean air passing through second auxiliaryfilter 512 is sucked into the motor-driven blower.

Cyclonic dust collector 560 is equipped with a pull-out handle (notshown) by which the user can take out the dust collector from thecleaner body. For disposal of dust, the user opens dust collector lid561 under dust collecting case 505 and dumps dust collecting case 505.As the dust collecting case 505 becomes wider downward, dust in dustcollecting case 505 is apt to fall to the bottom and dust can hardlyremain in dust collecting case 505.

As first auxiliary filter 506 is provided under dust collecting case 605to pass air, the flow resistance increases as dust accumulates further.With this, the dust in dust collecting case 505 is compressed. Furtheras first auxiliary filter 506 is on the bottom of dust collecting case505, dust is further compressed by its weight. Therefore, much more dustcan be accumulated in dust collecting case 505 and the dust dumpingfrequency can be made smaller. Further as fine particles such as lint,sands, and soil in dust are caught up in dust layers, rise up of finedust can be suppressed when the dust is disposed of.

The user can clean cyclonic separation cylinder 504 (when it is dirty)after taking out inner cylinder 531. This also enables the user to cleannet filter 533 of inner cylinder 531.

Further, the user can wash and clean first auxiliary filter 506 aftertaking the filter from filter frame 540. The first auxiliary filter ismade of washable foamed materials such as urethane sponge.

It is possible to simplify the air passages, reduce the height of thecleaner body, and make the cleaner body smaller and less weight byintroducing air from cyclonic separation cylinder 504 into innercylinder 531 and flowing air linearly to air outlet 520 therebelow (thanthose designed to introduce air from the inner cylinder downward throughthe outside of cyclonic separation cylinder 504). This mechanism caneliminate flow bending, loss due to air disturbance, and loss due tofriction. Consequently, this mechanism has an effect of increasing thesuction power.

Net filter 538 on the opening of part 534 of inner cylinder 531 does notcover the whole cylindrical part 534. The cylindrical part of about 90degrees near air inlet port 515 is formed with the wall of thecylindrical part 534. This prevents long dust particles such as hairs(sent from air inlet port 515) from directly hitting net filter 533,sticking into the net filter or being twined around with the net filter.Similarly, this prevents sharp-pointed materials such as pins andneedles (sent from air inlet port 515) from directly hitting net filter533, breaking the net filter, and leaking.

As already explained, the present invention can provide a small andeasy-to-operate cyclonic separation type dust collector by comprising acyclonic separation cylinder that swirls air upwards and a dustcollecting case that contains filters.

In accordance with the present invention, the center axis of thecyclonic separation cylinder is moved a little away from the center ofthe cleaner body and a motor-driven blower is placed opposite to thecyclonic separation cylinder. This can make the cleaner body shorter.

Further in accordance with the present invention, a cyclonic separationcylinder which takes in dirty air from downwards and discharges cleanair downwards and flowing part of clean air into a dust collecting casehaving a filter can provide a small easy-to-operate cyclonic separationtype dust collector of high dust-capturing performance.

1. A vacuum cleaner comprising: an electric vacuum cleaner main bodywithin which an electrically driven blower installed; a cyclonicseparation cylinder provided on said electric vacuum cleaner main bodyfor flowing dust containing air sucked from a suction port into an inlettube and removing dust according to a centrifugal separation; and aninner cylinder provided on said cyclonic separation cylinder having anexhaust air port; wherein said exhaust air port includes an openingportion arranged in a substantially parallel orientation with said inlettube.
 2. An electric vacuum cleaner according to claim 1, wherein saidelectric vacuum cleaner further comprises: a dust collecting caseprovided on said electric vacuum cleaner main body and having an openingwhich communicate with said cyclonic separation cyliner; a filterarranged on said dust collecting case; and a communicating passageformed separately from said cyclonic separation cylinder and said dustcollecting case for communicating with said exhaust air port; whereinair passed through said filter and air clown out from said communicatingpassage are merged, and said merged air is sucked into said electricallydriven blower.
 3. An electric vacuum cleaner according to claim 1 or 2,wherein a net filter is provided at a cylindrical portion of said innertube.
 4. An electric vacuum cleaner according to claim 1 or 2, whereinsaid cyclonic separation cylinder is formed with a substantiallycylindrical shape; and said inlet tube is arranged at a position whereair flows into at a substantially tangential direction to said cyclonicseparation cylinder.